49 research outputs found

    Hermit crabs (Pagurus spp.) at their northernmost range: distribution, abundance and shell use in the European Arctic

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    Hermit crabs are important components of Arctic benthic systems, yet baseline data on their densities and distribution patterns in this rapidly changing region are still scarce. Here we compile results of numerous research expeditions to Svalbard, the Barents Sea and northern Norway that were carried out from 1979 to 2011 by the Institute of Oceanology, Polish Academy of Sciences. The diversity of hermit crabs at the northern edge of their occurrence is very low; in Svalbard waters only one species (Pagurus pubescens) was detected. Another species (P. bernhardus), found in northern mainland Norway, north of the Arctic Circle, is likely to extend its distribution northward as the climate warms. Where the two species co-occur, competition between them probably accounts for the smaller sizes and poorer quality shells used by P. pubescens. The composition of the mollusc shells inhabited by these crabs differs between northern Norway and Svalbard, reflecting local mollusc species pools. Hermit crab densities were significantly higher than previously reported (max. mean 10 ind. m−2), suggesting their increasing level of dominance in benthic communities in the studied areas. The first to report the distribution of hermit crabs among habitats, this study showed that most individuals occurred at shallow depths (5–150 m), away from glacier termini and on hard bedrock rather than on soft substrata

    Mobilna edukacja – (R)ewolucja w uczeniu się - poradnik dla osób uczących się.

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    Publikacja z serii THINK! - WIRTUALNA BIBLIOTEKA NOWOCZESNEGO NAUCZYCIELA I UCZNI

    Biological properties of low-toxicity PLGA and PLGA/PHB fibrous nanocomposite implants for osseous tissue regeneration. Part I: evaluation of potential biotoxicity

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    In response to the demand for new implant materials characterized by high biocompatibility and bioresorption, two prototypes of fibrous nanocomposite implants for osseous tissue regeneration made of a newly developed blend of poly(L-lactide-co-glycolide) (PLGA) and syntheticpoly([R,S]-3-hydroxybutyrate), PLGA/PHB, have been developed and fabricated. Afibre-forming copolymer of glycolide and L-lactide (PLGA) was obtained by a unique method of synthesis carried out in blocksusing Zr(AcAc)4 as an initiator. The prototypes of the implants are composed of three layers of PLGA or PLGA/PHB, nonwoven fabrics with a pore structure designed to provide the best conditions for the cell proliferation. The bioactivity of the proposed implants has been imparted by introducing a hydroxyapatite material and IGF1, a growth factor. The developed prototypes of implants have been subjected to a set of in vitro and in vivobiocompatibility tests: in vitro cytotoxic effect, in vitro genotoxicity and systemic toxicity. Rabbitsshowed no signs of negative reactionafter implantation of the experimental implant prototypes

    The current possible treatment approaches of Polycystic Ovary Syndrome (PCOS)

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    Introduction             Polycystic ovary syndrome (PCOS), first described by Stein and Leventhal in 1935, is one of the most prevalent endocrine system conditions affecting women of reproductive age. It affects between 6% and 13% of women and the majority of cases are identified between the ages of 20 and 30. Unfortunately, the disease is usually diagnosed only when bothersome symptoms such as hair loss, alopecia, acne, and infertility-related problems occur. Based on the Rotterdam criteria, four phenotypes of PCOS are distinguished. Aim of the study             This review aims to present the current state of knowledge about possible treatment approaches, both non-pharmacological and pharmacological. Materials and methods            The paper was created based on the Pubmed database. The literature was reviewed using the keywords: ”PCOS”, ”PCOS treatment” and “ PCOS medications “. The current state of knowledge           Treatments for PCOS must be tailored to the specific needs of each patient. In the management of PCOS, special attention is paid to diet, physical activity, and restoration of the Gut Microbiome. Medications used in therapy are oral contraceptives and anti-androgens, insulin sensitizers, ovulation inducers, calcium and vitamin D supplements, statins, Glucagon-like-peptide-1 (GLP-1) agonists, inositols and interleukin 22 (IL-22)  therapy. Summary            Treatment options for menstrual irregularities and hirsutism are based on the clinical goals and preferences of the patient. The ideal would be causal treatment, but due to the ongoing lack of full understanding of the pathogenesis of the syndrome, is not entirely feasible. The ideal would be causal treatment, but due to the ongoing lack of full understanding of the pathogenesis of the syndrome, is not entirely feasible. The most important is a multimodal approach to treat comorbid conditions such as diabetes mellitus type 2, obesity, hyperlipidemia, depression, and infertility

    The multimodal approach to obesity treatment – current pharmacological and surgical methods and lifestyle changes

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    Introduction            Obesity is one of the major health problems of today’s population and is defined as a body mass index ≥ 30 kg/m2.  It is known that obesity may cause many complications such as type 2 diabetes, cardiovascular disease, osteoarthritis, obstructive sleep, apnoea, and several cancers. The only effective treatment of obesity can be pharmacological or surgical, especially when a years-long attempt to change habits has had no effects.  Aim of the study This review aims to present the current state of knowledge about non-pharmacological and pharmacological obesity treatment methods. Materials and methods            The paper was created based on the Pubmed database. The literature was reviewed using the keywords: ”obesity”, ”obesity treatment”, “ obesity lifestyle changes”, “obesity medications” and ”obesity surgery”. The current state of knowledge           The treatment of obesity requires a multimodal approach to treatment, including the addition of anti-obesity medications or bariatric surgery, or both, to assist people in reaching and sustaining sufficient weight loss to meet treatment goals. The 3 principal components of a comprehensive lifestyle intervention are diet, physical activity, and behavioral therapy. Among available anti-obesity medications include orlistat, phentermine, topiramate, naltrexone, bupropion, liraglutide, and semaglutide. Summary            The key challenge in the treatment of obesity is to maintain the effects obtained with multimodal therapy. Without proper motivation of patients and changes in eating and behavioral habits, it is impossible to achieve optimal results, therefore, in addition to medical interventions, more and more attention should be paid to psychological interventions

    Learning biophysically-motivated parameters for alpha helix prediction

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    <p>Abstract</p> <p>Background</p> <p>Our goal is to develop a state-of-the-art protein secondary structure predictor, with an intuitive and biophysically-motivated energy model. We treat structure prediction as an optimization problem, using parameterizable cost functions representing biological "pseudo-energies". Machine learning methods are applied to estimate the values of the parameters to correctly predict known protein structures.</p> <p>Results</p> <p>Focusing on the prediction of alpha helices in proteins, we show that a model with 302 parameters can achieve a Q<sub><it>α </it></sub>value of 77.6% and an SOV<sub><it>α </it></sub>value of 73.4%. Such performance numbers are among the best for techniques that do not rely on external databases (such as multiple sequence alignments). Further, it is easier to extract biological significance from a model with so few parameters.</p> <p>Conclusion</p> <p>The method presented shows promise for the prediction of protein secondary structure. Biophysically-motivated elementary free-energies can be learned using SVM techniques to construct an energy cost function whose predictive performance rivals state-of-the-art. This method is general and can be extended beyond the all-alpha case described here.</p

    Benthic Crustacea and Mollusca distribution in Arctic fjord – case study of patterns in Hornsund, Svalbard

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    We present the results of species distribution modeling conducted on macrobenthic occurrence data collected between 2002 and 2014 in Arctic fjord – Hornsund. We focus on species from Mollusca and Crustacea taxa. This study investigates the importance of individual environmental factors for benthic species distribution, with a special emphasis on bottom water temperature. It aims to verify the hypothesis that the distribution of species is controlled by low water temperatures in the fjord and that the inner basins of the fjord serve as potential refugia for Arctic species threatened by the climate change-related intensification of warmer water inflows. Our results confirm the importance of bottom water temperature in regulating the presence of benthic fauna in the Hornsund fjord. The distribution of studied species is clearly related to specific water mass – colder (1°C); and the preferred temperature regimes seem to be species specific and unrelated to analyzed groups. This study supports the notion that inner basins of the Hornsund fjord are potential refugia for cold water Arctic fauna, while the outer and central basins provide suitable habitats for fauna that prefer warmer waters

    Genome sequencing makes a significant progress in plant breednig

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    Sekwencjonowanie genomów jest odczytaniem zapisu genetycznego, jakim dany organizm dysponuje, wyrażonego w odpowiednim uporządkowaniu nukleotydów. W efekcie uzyskujemy informację rzeczywistą o strukturze i położeniu genów i innych składników genomu, co daje podstawy do szczegółowego prognozowania cech organizmu i pozwala wyjaśniać mechanizmy wielu reakcji. Z tych powodów efekty sekwencjonowania mają wielorakie implikacje, między innymi oddziałują na nauki rolnicze w szczególności na postęp hodowlany. W artykule przedstawione zostały uwarunkowania ogólne sekwencjonowania i przybliżono znaczenie niektórych danych jakie uzyskano u ogórka.Genome sequencing is the reading of the genetic record of a given organism, expressed in the correct sequence of nucleotides. In effect, information about the real structure, location of genes and other elements of a genome is obtained. It gives a solid base for detailed prediction of the organism's traits and allows explain the mechanisms of many metabolic reaction. This is why the sequencing has many implications, for example on agricultural science, especially in breeding programs. This article presents general sequencing strategies and gives a closer look at the meaning of experimental data obtained by cucumber
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